Soldering device and its operating system



Filed May 15, 1952 April 7, 1954 N. o. CLARK SOLDERING DEVICE AND ITS OPERATING SYSTEM 3 Sheets-Sheet l- 5/ INVENTOR.

B'Y/QI-.

JI'I'MA/E/ Ap 1954 N. o. CLARK 2,677,039

SOLDERING DEVICE AND ITS OPERATING SYSTEM Filed May 15, 1952 5 Sheets-Sheet 2 INVENTOR.

P75. 16' Agata/(l 0. (243K April 27, 1954 N. o. CLARK 2,677,039

SOLDERING DEVICE AND ITS OPERATING SYSTEM Filed May 15, 1952 3 Sheets-Sheet 3 F/Li 13.

I Illlll I p 5.9

. INVENTOR. 4 54 so 0. (242K Patented Apr. 21, 1954 AND ITS OPERATING SOLDERING DEVICE STEM Nelson 0. Clark, Winthrop, Mass. Application May 15, 1952, Serial No. 287,865

7 Claims. 1

This invention relates generally to soldering devices, including an electric system for operating them, and more particularly to soldering instrumentalities, the soldering points of which are normally heated to a sufficient degree to render soldering fluxes applied to them in a fluid state to prevent them from oxidizing and thus keeping them always ready for efiective soldering operations.

The principal objects of this invention are the provision of an electric system for soldering devices by' the use of which system a soldering instrumentality is normally supplied with a low current for' heating its soldering tips to a degree su'fii cient to render soldering flux fluid to cover their surface, thus preventing them from oxidizing, and in which system control means are provided to regulate the supply of current for effectuatingsoldering operations.

' Another object of this invetnion is the provision of, a soldering device in the form of workholding tweezers having electrically conductive, compressible blades terminating in soldering tips normally in contact with one another so as to permit flow of current through the tweezer blades fo'rfthe purpose of keeping the tweezer tips at a sufficient temperature to render flux applied to them. fluid condition.

Another objector this invention is the provision, of soldering tweezers with normally closed soldering tips and which tweezers comprise a pair of resilient compressible blades which are rigidly joined but electrically separated from one another at one of their ends and which blades, when compressed, will cause the soldering tips thereof to separate.

A still further object is the provision of a soldering device in the form of a tweezer structure composed of two resilient compressible blades which are rigidly joined but electrically separated from one another at one of their ends, while their other ends terminate in soldering tips which are normally maintained in'contact engagement with one another, and wherein the blades cross each other intermediate between their ends without touching at their crossing area, and wherein the normally contacting soldering tips are separable when the blades are compressed at points between their joined ends and their crossing area.

Another important object of this invention is the provision of tweezers as stated above, wherein are' provided heat insulating dielectric bladecoveringgripping means which are sufiiciently spacedfrom the-blades to provide air circulation about the blades for the purpose of cooling them and which gripping means, when compressed, are intended to facilitate the movement of the blades relative to one another for the purpose of opening their normally closed tip ends to facilitate gripping a work piece to be soldered.

Still another object of this invention is the provision of a soldering device of the type indicated, wherein the tweezer blades are made of material which is highly conductive electrically, and wherein the tips provided for the tweezer ends are made of another material having high contact resistance characteristics.

A still further object is the provisionv of a soldering device in the form of tweezers, wherein the blades are made of compositelayers of different materials, one of the layers having high electric conductivity while the other layer possesses a relatively low electric conductivity, and wherein the soldering tips are made, of still another material but which is integrated with the material of-the blades and possesses the characteristics of normally shedding solder, thus preventing the latter from adhering to the tips.

A still further object is the provision of soldering tweezers wherein the blades are made of a material being electrically conductive buthaving a low heat conductivity, and wherein the soldering tips are made of a different material but are integrated with the ends of the blades and having the characteristics of high contact resistance.

Still another object of this invention is the provision of a soldering device in the form of a tweezer structure having a pair of cooperating resilient electrically conductive blades which are fixedly joined but electrically separated at one of their ends, while their other ends are normally incontactwith one another, and wherein the blades are rendered compressible by means of outer dielectric insulating tweezer-gripping members which are associated with the bladesbut are spaced from them, and wherein the tweezer structure is provided with a switch unit which is adapted to be actuated duri'ng' "soldering operations.

A more specific object of this invention'is'to provide in combination with'a tweezer structure, a switchunit in the form of a mercury'switch tube'foreffecting the passage of heating current through'the tweezers when the latter are held in working position. v

Another specific object of this invention is the provision of a soldering device in theform of 'a tweezer-structure as stated above, provided'with a switch unit in the form of a'xnic'ro-s'witch which is disposed between the blades, and wherein a switch-operating lever is employed which, when compressed, will close the switch while the tweezers are being held in operative position...

Still another object of this invention is to provide a soldering device of the tweezer structure type wherein the soldering tips of the tweezers are provided with a material which has high contact resistance and which tweezer tips are intended to be permanently closed for the 1 use as a miniature soldering device for pin-point soldering of very small articles.

The foregoing and numerous other important objects and additional advantages of the present invention will becomes more fully understood from the ensuing description in conjunction with the accompanying drawings which, although illustrating specific structures, are intended to serve for explanatory purposes only and are not designed to restrict the present disclosure to the actual showing, and wherein:

Fig. 1 denotes av diagram of an electric system employing a soldering instrument in the form of a tweezer structure, the tips of which are permanently heated by a relatively low curi rent supply and are adapted to be heated to a higher degree for soldering operations;

Fig. 2 illustrates another form of an electric system modified from that shown in Fig. 1;

Fig. 3 is still another modification of a similar electric system with, a different form of current control;

Fig. 3a is a section taken along lines 3a3a of Fig. 3

Fig. 4 is a diagram of an electric system similar to. that. shown in. Fig. 3 with the employment of soldering tweezers equipped with a switch unit controlling the. supply of current for soldering operations;

Fig. 5 is a plan view of a, tweezer structure having blades composed of two layers of different electric. and heat. conductivity;

Fig. 6 is, a section taken along lines 6--6 of Fig. 5;v

Fig. 7 is afragmental enlarged plan view of the crossing area in. the tweezerstructure shown in Fig. 5;

Fig. 8 is a section through the tip-equipped ends of the tweezers shown in Fig. 5 v holding a work piece;

Fig. 9 is an enlarged section taken approximately along lines Sis-90f Fig. 5;

Fig. 10. is an. enlarged section taken along lines. ill-l0: of Fig. 6;?

Fig".- 11 is a section. taken along lines |I--II 01 Fig. 10.;

Fig. 12 is a plan view of a modified form of a tweezer structure employing a switch unitin the form of a. mercury switch;

Fig. 13 is; a. section. taken, along lines I.3-I3. ot'F'ig. 12;

Fig. 1,4 is a detail plan view' of the soldering tips of. the tweezersfshown in Fig. 12 wherein is indicated-the crossing area of the tweezers;

Fig. 15.. is a detail end. View of the. tweezer tips holding a workpiece;

Fig. 16 isa, plan view. disclosing a portion of. a modified tweezer structure. equipped. with a switch unit in theform of a micro-switch;

Fig. 17 is a section taken along lines l'I--II of Fig- 16. but. showing the. complete structure; and

s- 18 is. a fragmental Section. taken along linesl8.--|& of Fig. 17.,

The electric system In describing Figs. 1 to 4, it will be noted that in each of these illustrations there is employed a transformer ID, from one terminal of primary ID of which extends a lead II to one potential I2 of a source of energy, the other potential I3 of that source being connected in different manners in each of the four illustrations to the other terminal of the transformer primary, but in each case the current supply from that potential is controlled by a single pole, double throw, two-contact switch I4, the switch lever of which normally engages one of the contacts I5, but is adapted to be switched into engagement with normally free switch contact l6 whenever a supply of current is required for soldering operations.

In Fig. 1 a lead I1 extends from source potential I3 to a resistance [8 and from that resistance a lead I9 passes over contact point 20 to the other, upper terminal of transformer primary Ill. The primary is seen to be tapped at four points for the purpose of regulating the intensity of the current supply by means of a switch lever 2I connected by lead 22 to normally free contact I6 of switch I4. Resistance I8 may be substituted by a choke I8 indicated above that resistance. I

While switch I4 is in its normal position shown, resistance I8 or choke I8 permits but a limited current supply to pass into primary ID of the transformer, whereby a correspondingly limited current output from the transformer secondary 23 reaches the terminals of tweezer structure 24 and its normally contacting soldering tips 25. However, that limited current supply to the tweezer structure is suilicient to keep its tips constantly heated at a temperature at which the soldering flux applied to the tips will liquify and will be. kept in, fluid state so that it will cover the tips, prevent their oxidation, and render them ready always for eifective soldering operations.

For the purpose of efiecting such soldering operation, the tweezers are momentarily separated by compressing the tweezer blades. so that the tips may grip the work, piece to be soldered. while at. the, same time switch I4 is caused to disengage contact I5 and to engage contact I6. This. is preferably done by a foot pedal arrangement or other suitable means. so that both hands of the. operator are free. for use during soldering operations. Depending uponv the intensity of current required, tap lever ZI. is moved to the. desired primary tap point.

In Fig. 2 the primary of transformer I0 is shown without taps, and resistance l8, seen in.

Fig. l, is replaced by choke. coil I6,

but in' every other respect diagrams Iv and 2 are quite similar.-

In the diagram shown in Fig. 3, a tapped choke 26. is. introduced in theconnection between contact. I5 and the. upper terminal of transformer primary Ill, and tap lever 21 is. connected with normally open contact I6 of switch It. By ad justing tap lever 21 to any one of the taps of the choke the current supply to tweezer tips. 25 may be readily governed. The type of tweezer'24 shown in Fig. 3 is intended to have its tips normally in contact with one another, and in that embodiment, the tweezers serve as a miniature or pin-point solderingiron. the heating of which is regulated bytapped choke 26. It will beobserved also that the tweezertips'are equipped. with metalelements 2,8 which possess thecharac; l.

t'eristics of having high contact resistance. In other words these resistance elements are intended to become heated to a far greater degree than the tip ends or any other part of the tweezer blades. In order to hold these resistance elements in close adjacency with one another, tweezer blades 28' are resilient and. are biased toward each other and have clip-like, compressible extensions 28 encased in dielectric-and heatinsulating material and which are normally spaced from the blades bodies. By exerting slight pressure upon these extensions, the tips of the blades are separated and can be used for gripping articles to be soldered.

For the purpose of normally keeping the tip ends sufficiently warm to liqueiy the soldering flux,-the supply of current passes through the entire length of the choke coil while switch l4 engages contact l5. During actual soldering operation, however, switch 14 is moved to contact I6, and the intensity of the current for heating tip elements 28 to the desired degree is regulated by the setting of tap lever 21. The maximum current supply to the transformer primary is efiected by placing tap lever 21 in contact with the left-hand end ta of choke 26.

In the diagram illustrated in Fig. 4, which is very similar to that shown in Fig. 3, there is again employed a tapped choke 29 and a tap lever 30 for regulating the current supply to the transformer primary, however in this system contact [6 of switch I4 is connected with tap lever 30 through a switch unit 3| which forms a permanent part of tweezer structure 32. By placing tap lever 30 in contact with the different taps of choke 29 the current for heating the tips of the tweezer structure is controlled in the same way as explained in connection with Fig. 3. For actual soldering operation, however, when switch l4 engages contact 16, current to the tweezers is delivered only when the tweezers are held in operating or soldering position. At that position of the tweezers the switch unit closes the circuit to energize the primary and to supply heating current through the secondary to the tweezer points. Switch unit 3| may be either of the mercury tube structure or of a manually operated micro-switch type, as will be presently explained.

Soldering devices In Figs. 5 to 10 is shown structure wherein the blades are made of composite layers of material. In describing this tweezer structure in detail, numerals 33 and 34 denote the two tweezer blades which are permanently associated with one another at one of their ends by rivets, screws or other suitable means indicated at 35, but which are electrically insulated from one another by suitable dielectric material 36. At the outer surfaces of the blades are provided dielectric and heat-insulating gripping elements 31, assuring safe handling of the tweezers. This tweezer structure is of the type where the two tweezer blades cross each other as at 38 without touching one another at their crossing area by providing a suitable spacing 39 between the blades, see Figs. 5 and 'I. As will be observed especially from Fig. 6, the blades are composed of two layers of material having different characteristics, one of the layers having a lesser heat conductivity than the other, while the other layer has a higher electric conductivity. These layers are respectively indicated at 40 and 4 l layers 40 being made, for instance, of low heat conductivity stainless steel, whereas layers 41 are a specific tweezer with outwardly bent portions made of copper conductivity. It will be noted that the copper or silver layers 4| are placed along the interior surfaces of layers 40 where the blades are joined with one another,. while they cover the outer surfaces of layers 40 from the crossing area of the tweezers towards their tips. It will be also noted that to the narrow blade ends 42 are secured by welding or otherwise soldering tips 43, preferably made of tungsten or any other suitable material which will resist solder from depositing and thus preventing it from readily adhering to the tips. These tips ment to the blades through their secure attachbecome integral parts of the blade material.

Tweezer structures provided with switch units operable while the tweezers are being used are illustrated in Figs. 12 to 18. In Figs. 12 to 14:.

there is shown a tweezer structure equipped with a mercury switch, while the form shown in Figs. 16 to 18 is provided with a hand-operated microswitch.

In the embodiment of Figs. 12 to 14 it will be noted that the tweezer blades 44 are provided 45 and that their crossing area 46 is located near the very narrow blade tips 41. The left end of blades 44 are fixedly held together by means of rivets, screws or any other means 48, but are insulated from one another by dielectric spacers 49. Similar spacers 50 are employed for separating these blades from dielectric heat insulating elements 52 which are adapted to engage the bowed-out portions 45 of the blades but which are otherwise spaced from the blade bodies so as to provide air circulation all around the blades. Also held by rivets 48 is a frame 53 in which is mounted a mercury switch 54 which controls the supply of current to the terminals of the blades.

The crossing area of the blades is clearly shown in Fig. 14 where a spacing 55 between the blades is clearly indicated. In Fig. 15 the narrow tips 41 are shown separated and holding a work piece 56. Tips 41 are brought to their work piece holding position when the blades are compressed as insulating elements 52 are forced toward one another.

The tweezer construction shown in Figs. 16, 1'1 and 18 is very similar to that described in connection with Figs. 12 to 15. Here again two blades 51 are shown which are spaced and insulated from one another and are held together by screws 58 and 58 at one end, while their other end terminates in normally contacting soldering tips 59 which cross each other at 60 without touching at their crossing area. The spacing between blades 51 at their connected ends is much greater than the blade spacing shown in Fig. 13, and in that wider space there operates a dielectric lever 6| which is pivoted about screw 58 but can swing in relation to screw 58' by reason of an oval aperture 62 provided in the lever body, as clearly seen in Fig. 18.

Secured between the blades is a micro-switch 63, the operation of which is effected by the movement of lever BI, and which switch controls the supply of current to blades 51. It will be noted from Fig. 11 that exterior to the blades are arranged dielectric insulating elements 54 provided with extensions 65 in engagement with blades 51. These dielectric elements facilitate the gripping of the tweezer structure and prevent the hand holding the tweezers from being injured by either the current passing through or the heat emanating from the tweezer blades.

or silver of high electric and heat;

described, it is quite obvious that, depending as defined in the annexed claims.

What is claimed as new is:

1. In an electric system for soldering devices, soldering tweezers having manually separable but normally contacting, heatable, work-engagthe impedance, a switch unit forming a part of the tweezers, one terminal of the switch unit 3. In an electric system according to claim 2, and wherein said tweezer blades are made ,of

characteristics.

4. In an electric system according to claim 2,

and wherein said tweezer blades are made if tweezers and being operative while the latter is being used for soldering operations.

6. In an electric system according to claim 5, and wherein said switch unit comprises a mer cury switch.

'7. In an electric system according to claim 5, and wherein said switch unit comprising a microswitch, said tweezers having means for actuating said microswitch.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date I 450,266 Tr-uax Apr. 14, 1891 485,017 Ries Oct. 25, 1892 1,435,470 Hosford Nov. 14, 1922 1,659,911 Fay Feb. 21, 1928 1,807,004 Nelson May 26, 1931 2,106,436 Schubert Jan. 25, 1938 2,449,521 Warner Sept. 14, 1948 2,577,515 Durst Dec. 4, 1951 2,595,683 Lo Monte May 6, 1952 2,619,576 Greibach Nov. 25, 1952 2,623,152 Ammon Dec. 23, 1952 FOREIGN PATENTS Number Country Date 208,590 Switzerland May 1, 1940 380,026 Great Britain Sept. 8, 1932 

